The Crucial X6 is a USB solid state drive that I keep recommending, as it offers dependable SATA SSD speeds in a convenient yet rugged form factor. It comes in sizes from 500GB to 4TB, and now that massive biggest size is discounted: just £225, down from a UK RRP of £475 for a cool £250 discount.
The 4TB X6 was selling for £300+ as recently as Halloween, so to see it for £225 a month later is exciting news. Looking online, it's hard to find anything as big for as cheap - the SanDisk Extreme 4TB is £380 even on Black Friday discount, while the faster Crucial X8 is still £265 despite being an Amazon EU import.
Here's what I said about the X6 last time it was discounted (previously it was the 2TB size):
The Crucial X6 was recently upgraded, and now supports sequential read and write speeds up to 800MB/s, making it much closer in performance to the more expensive Crucial X8. Of course, as well as offering faster file transfers, the drive also offers considerably lower latency than a portable hard drive - you can actually play games off of this without issue, which is incredible. Likewise, if you use this to store media like videos or images, then you can pull them up instantly, rather than needing to wait for a mechanical hard drive to slowly spool up.
These Crucial drives are genuinely great. I use its bigger brother, the Crucial X8, here at home, where it's been a revelation for quickly backing up files, moving downloaded videos onto the downstairs TV or simply keeping games ready to play at a moment's notice. Note that the Crucial X6 has a different form factor than the X8 - it's more of a squircle than the oblong X8, and caps out at around 800MB/s rather than around 1000MB/s - but both models do the same thing; the only real difference is how long you'll be waiting for a file transfer to complete.
In any case, the X6 at this price is what I'd go for over the faster X8 - but what do you think? Let me know in the comments below, and stay tuned for more discounted tech goods on Cyber Monday as the festivedealstraganzeriod continues!